Online Contest “Mathematics and Art” for the Development of Key Competencies

The online contest “Mathematics and Art” is organized by Tonediko since 2015. Participation in it creates the opportunity to develop almost all key competences. In addition, the competition is a means of promoting digital mathematical tools to a wide audience. In the paper, in the context of the research of the ability to use the provided dynamic files (directly or after modification), to create a composition on a given topic, the following will be presented: the competition regulation; main activities of the participants; opportunities to use the competition in IT lessons, fine arts, labor and equipment, mathematics and related teacher activities; results of passed competitions, some challenges and options to overcome them.

BLEH: Bit-Less Extendible Hashing for DBMS and Hard Disk Drives

Indexing techniques such as extendible hashing and B-trees are widely used to store, retrieve and search for data on files in most file systems. These techniques have been comprehensively explored to enhance the data structure for increasing the faster access to file contents. Extendible hashing is a dynamic hashing technique which handles dynamic files that keep changing in size. Traditional extendible hashing uses bit addresses to hash the data to buckets and restricts the directory size to be a power of 2 which has corresponding complications in implementation. Restriction on directory size also results in uneven distribution of data which increases the possibility of overflows. This in turn increases the cost of index maintenance. In this paper, an efficient and simpler to implement variation of Extendible hashing method named Bit-Less Extendible Hashing (BLEH) for dynamic files is proposed. The proposed method eliminates the need for binary representation of the hash address which reduces the complexity of implementation. Furthermore, it eliminates the need for the directory size to be a power of 2 providing flexibility in the choice of initial directory size. The experimental results show that the proposed method provides better performance in terms of split count upon insertion when compared to the traditional extendible hashing method with good space utilization.

Metadata Provenance and Vulnerability

The preservation of digital objects has become an urgent task in recent years as it has been realised that digital media have a short life span. The pace of technological change makes accessing these media more and more difficult. Digital preservation is accomplished by two main methods, migration and emulation. Migration has been proven to be a lossy method for many types of digital objects. Emulation is much more complex; however, it allows preserved digital objects to be rendered in their original format, which is especially important for complex types such as those made up of multiple dynamic files. Both methods rely on good metadata in order to maintain change history or construct an accurate representation of the required system environment. In this paper, we present our findings that show the vulnerability of metadata and how easily they can be lost and corrupted by everyday use. Furthermore, this paper aspires to raise awareness and to emphasise the necessity of caution and expertise when handling digital data by highlighting the importance of provenance metadata.

Cognitive dynamics

This chapter offers an elaboration and defense of the mental-file approach to singular thought. Mental files are supposed to account for both cognitive significance and coreference de jure. But these two roles generate conflicting constraints: files must be fine-grained to play the first role and coarse-grained to play the second role. To reconcile the constraints, we need to distinguish two sorts of file (static files and dynamic files), and two forms of coreference de jure (strong and weak). Dynamic files are sequences of file-stages united by the weak coreference de jure relation. It is at the synchronic level, that of file-stages, that the stronger coreference de jure is to be found. The resulting view is compared to that of Papineau, according to whom only dynamic files are needed, and to that of Ninan, according to whom there are proper dynamic files that exhibit strong coreference de jure.

Knowledge Management for Plant Shutdown in Collaborative Virtual Reality

Oil refineries run nearly continuously twenty-four hours a day. The process of doing routine maintenance, adding or rebuilding refinery process rigs and powering down is referred to as "shutdown". Refineries are extraordinarily complicated and shutdowns are therefore very problematic and expensive. Poorly planned or executed shutdown can result in loss of life and millions of dollars of lost productivity. There is also an important collaborative and knowledge management aspect in that all shutdowns involve many people and are executed by temporary contractors who are often unfamiliar with the details of the plant they are shutting down. Commonly, text and two dimensional drawings are used in preparation for a plant shutdown and exchanging of information. However, with the advent of new technologies it is now possible to also exchange knowledge three dimensionally including multimedia and dynamic files. One technology that enhances the knowledge exchanging and management is Collaborative Virtual Reality Environment (CVRE). CVREs allow users to interact with a computer-simulated environment, be it a real or imagined while using the Internet to collaborate and interact with possibly many other users that may be spread over large distances. Virtual Reality has been widely applied in various forms to plant shutdown planning but the knowledge management aspect of the process is not being addressed by these technologies. In this paper we describe the early use and underlying details of an innovation implantation of a Collaborative Virtual Whiteboard (CVW) inside of an CVRE